 He was a Parliamentary candidate at the 1929 and 1931 general elections for Gainsborough, and in the 1935 general election he fought in Lincoln where he lost by 2,684 votes.While serving as Sheriff of Lincoln in 1943–44, Deer was made a member of the Order of British Empire in the New Years' Honours list of 1944.He had been reselected as Labour candidate for Lincoln, and in the 1945 general election he was elected.